The present invention relates to wireless communication systems in general and, more particularly, to a system and method for acquiring service on a more desirable system when receiving service from a less desirable system.
Wireless communication systems, such as cellular telephones, are commonly used as a replacement for conventional telephone systems. A large number of service providers are actively competing for market share in multiple geographic regions. An individual user typically subscribes to a selected service provider and uses a wireless telephone device that is compatible with the service provider.
A user typically has a contractual obligation to the service provider wherein all billing for the wireless telephone is provided by the service provider. Indeed, users typically select service providers based on the financial arrangements of the contract and upon the areas of service coverage provided by the service provider. When the user operates the wireless telephone in a xe2x80x9chomexe2x80x9d region, service to the wireless telephone is typically provided by the user-selected service provider. When the user is outside the home region, the wireless telephone is said to be operating in a xe2x80x9cRoamxe2x80x9d mode. When operating in the Roam mode, the wireless telephone may be connected to the user-selected service provider, or some other service provider if the user-selected service provider cannot service to the wireless telephone. In either case, billing still occurs through the user-selected service provider. In the former situation, billing may be provided directly from the service provider. In the latter case, the billing from the actual service provider is forwarded to the user-selected service provider.
The wireless telephone is typically preprogrammed with the data related to various service provider systems taking into account the particular capabilities of the wireless telephone. For example, it is well known that wireless telephones can operate in either an analog mode or a digital mode, and in a cellular band or a personal communication system (PCS) band. Some wireless telephones are capable of operating in both the analog mode and the digital mode (although only one mode at a time), and some wireless telephones are capable of operating in both the cellular band and the PCS band (although only one band at a time). For a wireless telephone to communicate effectively, it must be within the operational boundaries of a wireless communication system service provider that supports the same mode and band with which the wireless telephone was designed to operate.
When first powered up, wireless telephones scan for a service provider whose system is compatible with the wireless telephone. Depending on the service provider and the corresponding mode/band, a service provider system may or may not be compatible. Typically, there are several hundred service provider systems that are programmed into the wireless telephone. The wireless telephone must sequentially scan the entire list in an attempt to acquire service. As a result, the service acquisition process can be cumbersome and consume a significant amount of time.
This cumbersome nature is reduced by the fact that conventional telephones normally look on only 42 PCS channels, or 2 or 4 cellular channels (depending on whether the cellular channels are configured for Code Division Multiple Access (CDMA) or Advanced Mobile Phone System (AMPS)). Once service is acquired, the telephone attempts to determine if the acquired system is one of the several hundred compatible systems. The process is thus seem as remaining quite cumbersome, albeit not quite as cumbersome as it first appeared. Therefore, it can be appreciated that there is a significant need for a system and method to reduce the number of service provider systems that must be scanned for service, thereby minimizing the typical time to acquire a service provider system. The present invention provides this and other advantages as will be apparent from the following description and accompanying figures.